Mediastinal adipose tissue expresses a pathogenic profile of 11 ß-hydroxysteroid dehydrogenase Type 1, glucocorticoid receptor, and CD68 in patients with coronary artery disease.

OBJECTIVE: Cardiac visceral fat is accepted to be a new marker for cardiometabolic risk due to its association with increased cardiovascular risk factors. This study aimed to compare the expression of 11 beta hydroxysteroid dehydrogenases (11ß-HSD)-1, glucocorticoid receptor (GCR), and CD68 in mediastinal and subcutaneous adipose tissues (MAT, and SAT, respectively) and to assess their possible relationships with the development of coronary artery disease (CAD). METHODS AND RESULTS: Expression of 11ß-HSD-1, GCR, and CD68 mRNA levels were measured by quantitative real-time polymerase chain reaction in MAT and SAT tissues of 37 patients undergoing coronary artery bypass grafting due to CAD (CAD group) and 19 non-CAD patients (controls) undergoing heart valve surgery. 11ß-HSD-1 in MAT and SAT and GCR expression in MAT and SAT were found to be significantly increased in CAD group when compared with controls (P<.05, respectively). In CAD group, 11ß-HSD-1 mRNA levels were found to be significantly higher in MAT compared to SAT (P<.05). CD68 mRNA levels were significantly higher in MAT of CAD group compared to controls (P<.05). Immunohistochemical analyses demonstrated the presence of CD68+ cells and increased 11ß-HSD-1 expression in MAT of CAD group compared to SAT. CONCLUSION: The present study demonstrate that the mediastinal fat exhibits a pathogenic mRNA profile of 11ß-HSD-1, GCR, and CD68. The identification of 11ß-HSD-1 expression within the mediastinal fat, along with increased GCR expressions and the presence of CD68+ cells highlight that MAT potentially contributes to the pathogenesis of CAD.

The role of mediastinal adipose tissue 11ß-hydroxysteroid d ehydrogenase type 1 and glucocorticoid expression in the development of coronary atherosclerosis in obese patients with ischemic heart disease.

BACKGROUND: Visceral fat deposition and its associated atherogenic complications are mediated by glucocorticoids. Cardiac visceral fat comprises mediastinal adipose tissue (MAT) and epicardial adipose tissue (EAT), and MAT is a potential biomarker of risk for obese patients. AIM: Our objective was to evaluate the role of EAT and MAT 11beta-hydroxysteroid dehydrogenase type 1 (11ß-HSD-1) and glucocorticoid receptor (GCR) expression in comparison with subcutaneous adipose tissue (SAT) in the development of coronary atherosclerosis in obese patients with coronary artery disease (CAD), and to assess their correlations with CD68 and fatty acids from these tissues. METHODS AND RESULTS: Expression of 11ß-HSD-1 and GCR was measured by qRT-PCR in EAT, MAT and SAT of thirty-one obese patients undergoing coronary artery bypass grafting due to CAD (obese CAD group) and sixteen obese patients without CAD undergoing heart valve surgery (controls). 11ß-HSD-1 and GCR expression in MAT were found to be significantly increased in the obese CAD group compared with controls (p < 0.05). In the obese CAD group, 11ß-HSD-1 and GCR mRNA levels were strongly correlated in MAT. Stearidonic acid was significantly increased in EAT and MAT of the obese CAD group and arachidonic acid was significantly expressed in MAT of the obese male CAD group (p < 0.05). CONCLUSIONS: We report for the first time the increased expression of 11ß-HSD-1 and GCR in MAT compared with EAT and SAT, and also describe the interrelated effects of stearidonic acid, HOMA-IR, plasma cortisol and GCR mRNA levels, explaining 40.2% of the variance in 11ß-HSD-1 mRNA levels in MAT of obese CAD patients. These findings support the hypothesis that MAT contributes locally to the development of coronary atherosclerosis via glucocorticoid action.

Adipose tissue gene expression of adiponectin, tumor necrosis factor-α and leptin in metabolic syndrome patients with coronary artery disease.

OBJECTIVE: Metabolic syndrome (MS) is associated with an increased risk of coronary artery disease (CAD) and type 2 diabetes mellitus (DM). In MS, adipose tissue has been shown to function as a paracrine and an endocrine organ secreting various adipocytokines. In the current study, adiponectin, tumor necrosis factor-α (TNF-α) and leptin gene expressions in the epicardial adipose tissue (EAT), paracardial adipose tissue (PAT) and subcutaneous adipose tissue (SAT) were investigated in MS patients with CAD and in non-MS patients without CAD. METHODS AND RESULTS: Thirty-seven patients with MS undergoing coronary artery bypass grafting due to CAD (MS group) and twenty-three non-MS patients without CAD undergoing heart valve surgery (control group) were recruited prospectively to the study. Relative gene expressions of adiponectin, TNF-α and leptin in EAT, PAT and SAT were compared between two groups of patients. Adiponectin gene expression in EAT and PAT were significantly lower in MS group compared to the control group (p<0.0001, p=0.04, respectively) while SAT adiponectin gene expression did not differ significantly (p=0.64). TNF-α and leptin gene expressions were found to be statistically significantly higher in EAT, PAT and SAT of the MS group (p<0.0001, for all). CONCLUSION: Our results demonstrate that TNF-α and leptin gene expressions increase prominently in the EAT, PAT and SAT while adiponectin gene expression decreases significantly in EAT and PAT in MS patients with CAD. These findings suggest that disturbances in expression of adiponectin, TNF-α and leptin in EAT, PAT and SAT might play an important role in MS patients with CAD.

Presence of fatty-acid-binding protein 4 expression in human epicardial adipose tissue in metabolic syndrome.

BACKGROUND: Metabolic syndrome is a cluster of different clinical manifestations that are risk factors for atherothrombotic cardiovascular disorders. Fatty-acid-binding protein 4 (FABP4/aP2), which is highly expressed in adipocytes, specifically exerts intracellular lipid trafficking. A high level of fatty-acid-binding protein 4 expression present in obese subjects has also been found in mice and humans, especially in macrophages at atherosclerotic lesions. An in vivo study demonstrated that the inhibitor of aP2 would be a new therapeutic agent for treating metabolic diseases in mice. We have investigated the mRNA expression of fatty-acid-binding protein 4 in human epicardial adipose and ascending aorta tissues of metabolic syndrome and nonmetabolic syndrome patients. METHODS: Paired epicardial adipose and ascending aorta tissue samples were obtained from 10 metabolic syndrome patients and 4 nonmetabolic syndrome patients during coronary bypass grafting and aortic valve replacement therapy, respectively. Fatty-acid-binding protein 4 gene expression was determined by quantitative real-time polymerase chain reaction. RESULTS AND CONCLUSIONS: Fatty-acid-binding protein 4 expression of epicardial adipose tissue was significantly higher in metabolic syndrome patients than in nonmetabolic syndrome controls (P<.05). In metabolic syndrome patients, fatty-acid-binding protein 4 expression in epicardial adipose tissue was 66 times higher than fatty-acid-binding protein 4 expression in ascending aorta tissue. The expression level of fatty-acid-binding protein 4 in epicardial adipose tissue was found to be significantly correlated with waist circumference in all subjects (r=.535, P<.05). Our data showed for the first time that human epicardial adipose and ascending aorta tissues express fatty-acid-binding protein 4 and that its level of expression in epicardial adipose tissues of metabolic syndrome patients is elevated. Increased fatty-acid-binding protein 4 gene expression in epicardial adipose tissues of metabolic syndrome patients led us think that fatty-acid-binding protein 4 might be an important factor in metabolic syndrome.